Patterned boiled egg and process for producing the same

ABSTRACT

The curved surface inside the egg shell of an edible boiled egg is decorated by patterning so as to satisfy consumes&#39; needs for a tasteful table setting. The pattern is formed by using exclusively the inherent components of the egg without introducing any foreign matter thereinto, which causes no fear from the viewpoint of food sanitation management. On the albumen layer ( 9   b  or  21   a ), serving as the background, which has been formed by the coagulation of the albumen ( 3   c ) on the curved surface of the boiled egg, a pattern layer ( 19   a ) is formed by the coagulation of the yolk ( 3   g ). On the yolk layer ( 9   a  or 3 gf ), serving as the background, which has been formed by the coagulation of the yolk ( 3   g ) on the curved surface of the boiled egg, a pattern layer ( 3   e ) is formed by the coagulation of the albumen. These pattern layers ( 19   a  and  3   e ) are formed by site-selectively and intensively heating the outer surface of the egg shell ( 3   d ).

TECHNICAL FIELD

The present invention relates to a boiled egg cooked by boiling an egg,such as an egg of a hen or duck, dipped wholly or partially in a beatingmedium, such as hot water, and a method for producing the boiled egg,more particularly to a boiled egg with a pattern, on its curved surfaceafter removal of its eggshell, drawn by a yolk pattern layer coagulatingin an egg white skin layer coagulating, so as to form the curved surfaceof the boiled egg after removal of the eggshell, or reversely, drawn byan egg white layer coagulating in a yolk skin layer, and a method forproducing the boiled egg.

BACKGROUND ART

A boiled egg itself is a foodstuff habitually eaten from ancient times,and even during the present it is frequently eaten as it is; the way ofcutting has been improved, and a boiled egg is used only forornamentation on the dining table as a garnish and thus generallyremains as a commonplace foodstuff. Aside from the drawing of patterns,characters and figures on the outer surface of the eggshell, inconventional attempts to draw patterns or the like on the curved surfaceof the boiled egg after removal of the eggshell, coloring matters areinserted under pressure or penetrated area-selectively in some form fromthe outside of the eggshell through the eggshell, and the coloringmatters are impregnated on the curved surface of the boiled egg to drawpatterns; hence, there are dangers that microorganisms may enter throughminute damaged portions of the eggshell owing to the insertion underpressure and penetration treatment of the coloring matters, or thatcontaminants may enter because of the treatment itself;commercialization of such drawing is thus obstructed owing to concernsabout food hygiene control.

As such a prior art, Japanese Unexamined Patent Publication No. Hei2-249469 discloses a boiled egg, wherein numerous minute holes areprovided by perforation on the surface of the eggshell, and desiredpatterns or characters are color-printed on the curved surface of theegg white, or seasonings are penetrated to provide a flavor, from theoutside through the eggshell with the eggshell unremoved.

Furthermore, Japanese Unexamined Patent Publication No. Hei 2-27962discloses a yolk/egg white reversed boiled egg having a reversedarrangement of the yolk and egg white in an eggshell without using anyadditives from the outside, wherein small holes are provided at both theacute end portion and the obtuse end portion of the egg, air is suppliedunder pressure from one small hole into the eggshell to discharge theegg white through the other small hole to the outside of the eggshell,and the yolk remaining inside the eggshell is heated together with theeggshell so that the yolk coagulates and is attached to the inner faceof the eggshell to form an outside yolk layer; next, the discharged eggwhite is poured into the inside of the outside yolk layer through theone small hole, and the egg white is heated together with the eggshellso that the egg white coagulates at the central portion of the egg withthe outside of the egg white surrounded by the yolk layer. An eggproduced in this way also has a danger in food hygiene control.

Regarding food proceeding to be carried out for the egg white and yolkinside the eggshell without any concerns about entry of microorganismsthrough the minute damaged portions of the eggshell and entry ofcontaminants because of the coloring treatment itself in the prior art,Japanese Unexamined Patent Publication No. Hei 2-211850 discloses amethod for stirring and mixing the yolk and egg white in an eggshell bytearing the yolk film by manually swinging an egg accommodated in acylindrical egg container made of nylon. The egg processed and providedby this method is advantageous in food hygiene control since only thematerials inside the eggshell are used; however, this egg is a strange“thick omelet-like” boiled egg covered with eggshell; although theadvantage in food hygiene control is ensured, this egg is far inferiorto a “thick omelet-like” fried egg in terms of seasoning, wherein theegg is commonplace as a cooked egg; in particular, the curved surface ofthe egg with the eggshell removed is monotonous, uniform and dull incolor, whereby the egg does not provide an attractive tastefulness onthe dining table.

As desired above, in the prior art, two trade-off requests, i.e., foodhygiene control and tastefulness on the dining table, are not fulfilledadequately, thereby causing a problem of incomplete satisfaction in theornamental expression on the curved surface of the boiled egg with theeggshell removed with respect to tastefulness on the dining table.

DISCLOSURE OF THE INVENTION

In view of the problem of satisfaction in tastefulness on the diningtable in the above-mentioned prior art, the present invention isintended to provide ornamental patterns in two colors, white and yellow,by drawing a pattern by a yolk pattern layer formed area-selectively inan egg white skin layer on the curved surface of the boiled egg with itseggshell removed, and by drawing another pattern by an egg white patternlayer formed area-selectively in a yolk skin layer on the curved surfaceof the boiled egg, whereby the satisfaction of consumers with respect totastefulness on the dining table is improved without introducing anymaterials inside the eggshell.

As a first aspect of the present invention for solving theabove-mentioned problems, the invention set forth in claims 1 through 3is claimed.

The configuration of the invention set forth in claim 1 relates to astructure of a patterned boiled egg, wherein, as shown in FIG. 9, a yolkskin layer 9 a is formed of a yolk coagulating along nearly one half ofthe curved surface of the boiled egg, an egg white pattern layer 3 e isformed of an egg white coagulating so as to draw a pattern against thebackground of the yolk skin layer 9 a while eliminating the yolk nearthe curved surface inside the yolk skin layer 9 a, and an egg white skinlayer 9 b is formed of the egg white coagulating along nearly the otherhalf of the curved surface, other than the yolk skin layer 9 a.

The configuration of the invention set forth in claims 2 and 3 relatesto a method for producing the patterned boiled egg having the structureof the invention set forth in claim 1, comprising a first step, i.e., anegg white pattern layer forming step, for forming an egg white patternlayer so as to draw a pattern by heating a specific pattern area drawnon nearly one half of the curved surface of the eggshell of an eggarea-selectively and concentrically, by coagulating an uncoagulated eggwhite on the inner face of the eggshell, and by removably attaching theuncoagulated egg white to the inner face of the eggshell; a second step,i.e., a rotating/stopping yolk film tearing step used as a yolk filmtearing step, for tearing the yolk film, during the rotation of the eggaround the major axis of the egg at a high speed of about 3,600 rpm, byimmediately stopping the rotation and by applying a shearing force owingto the difference between the inertial force acting on the yolk at thecentral portion inside the eggshell and the inertial force acting on theegg white at the peripheral portion to the yolk film at the time of theimmediate stop; a third step, i.e., a yolk positioning step, forpositioning the uncoagulated yolk by floating the uncoagulated yolkafter the tearing of the yolk film in the egg white inside the eggshelland by positioning the uncoagulated yolk so that the uncoagulated yolksurrounds the egg white pattern layer attached to the inner face of theeggshell and makes contact with the egg white pattern layer; a fourthstep, i.e., a half yolk skin layer forming step, for forming a half yolkskin layer along nearly one half of the curved surface of the egg byboiling the egg, in which the uncoagulated yolk is positioned, in itsstationary posture as it is in a heating medium, such as hot water, andby coagulating the uncoagulated yolk so that the uncoagulated yolksurrounds the egg white pattern layer, makes contact with the egg whitepattern layer and becomes the background of the egg white pattern layer;and a simultaneously proceeding fifth step, i.e., a half egg white skinlayer forming step, for forming a half egg white skin layer along nearlyone half of the curved surface on the opposite side of the half yolkskin layer by boiling the egg, in which the uncoagulated yolk ispositioned, in its stationary posture as it is in a heating medium, suchas hot-water, and by coagulating the egg white sinking below theuncoagulated yolk floating in the eggshell.

In accordance with the configuration of the invention set forth inclaims 1 through 3 claimed as the above-mentioned first aspect, thecurved surface of the boiled egg with its eggshell removed is nearlyhalved; a pattern is clearly drawn in two colors in the yellow half yolkskin layer disposed on nearly one half by the white egg white patternlayer, and the white half egg white skin layer is disposed on nearly theother half other than the yellow half yolk skin layer; hence, thecontrast of the halves of the curved surface is intensified inornamental expression, thereby providing a tasteful boiled egg.

As a second aspect of the present invention for solving theabove-mentioned problems, the invention set forth in claims 4 through 7is claimed.

The configuration of the invention set forth in claim 4 relates to astructure of a patterned boiled egg, wherein, as shown in FIG. 16, awhole yolk skin layer 3 gf is formed of a yolk coagulating along thewhole curved surface of the boiled egg, an egg white pattern layer 3 eis formed of an egg white coagulating so as to draw a pattern againstthe background of the whole yolk skin layer 3 gf while eliminating theyolk near the curved surface inside the whole yolk skin layer 3 gf.

The configuration of the invention set forth in claim 5 relates to amethod for producing the patterned boiled egg having the structure ofthe invention set forth in claim 4, comprising a first step, i.e., anegg white pattern layer forming step, for forming an egg white patternlayer similar to that set forth in claim 2; a second step, i.e., a yolkfilm tearing step for carrying out a film tearing step similar to theyolk film tearing step set forth in claim 2; a third step, i.e., a wholeyolk skin layer forming step, for forming a whole yolk skin layer alongthe whole curved surface of the egg so that the whole yolk skin layerbecomes the background of the egg white pattern layer by sequentiallyexposing the whole face of the curved surface of the egg to a heatingenvironment while rotating the egg including the uncoagulated yolk afterfilm tearing, by floating the yolk in the egg white inside the eggshell,by attaching the yolk to the eggshell and by sequentially coagulatingthe uncoagulated yolk surrounding the egg white pattern layer and makingcontact with the egg white pattern layer near the inner face of theeggshell at the portion exposed to the heating environment duringrotation and rocking or immediately after rotation and rocking.

The configuration of the invention set forth in claim 6 relates to theexecution of the whole yolk skin layer forming step in the method ofproducing the patterned boiled egg set forth in claim 5, comprising afirst sub-step, i.e., a central portion yolk skin layer forming step,for forming a central portion yolk skin layer along the curved surfaceof a portion corresponding to the central portion along the major axisof the curved surface of the egg by sequentially exposing the portioncorresponding to the central portion along the major axis of the curvedsurface of the egg to an upper heating environment while rotating theegg around the major axis of the egg used as its horizontal rotationcenter axis, and by sequentially coagulating the uncoagulated yolkfloating in the egg white inside the eggshell and attached to theeggshell near the inner face of the upper portion of the eggshellexposed to the overheating environment during the rotation; a secondsub-step, i.e., an acute end portion yolk skin layer forming step, forforming an acute end portion yolk skin layer along the curved surface ofthe acute end portion by exposing the acute end portion of the egg tothe upper heating environment while rotating the egg around the majoraxis of the egg used as its inclined vertical rotation center axis, andby coagulating the uncoagulated yolk floating in the egg white insidethe eggshell at the acute end portion and attached to the eggshell; anda third sub-step, i.e., an obtuse end portion yolk skin layer formingstep, for forming an obtuse end portion yolk skin layer along the curvedsurface of the obtuse end portion by boiling the egg in a heatingmedium, such as hot water, in a stationary posture wherein the majoraxis of the egg extends vertically and the obtuse end portion ispositioned upward, and by coagulating the uncoagulated yolk floating inthe egg white inside the eggshell at the obtuse end portion and attachedto the eggshell.

The configuration of the invention set forth in claim 7 relates to theexecution of the whole yolk skin layer forming step in the method ofproducing the patterned boiled egg set forth in claim 5, comprising afirst sub-step, i.e., a rotating/rocking whole yolk skin layer formingstep, for forming a whole yolk skin layer along the whole curved surfaceof the egg, by boiling the egg while rotating the egg around the majoraxis of the egg mainly used as its rotation center axis and whilerocking the egg around the minor axis of the egg mainly used as itsrocking center axis in a state wherein the egg is wholly dipped in aheating medium, such as hot water, and by coagulating the uncoagulatedyolk, which is relatively easy to coagulate, floating near the innerface of the upper portion of the eggshell and attached to the eggshell,earlier than the uncoagulated egg white, which is relatively difficultto coagulate, sinking near the inner face of the lower portion of theeggshell and attached to the eggshell, during the rotation and rocking.

In accordance with the configuration of the invention set forth inclaims 4 through 7 claimed as the above-mentioned second aspect, ayellow whole yolk skin layer is formed so as to cover the whole of thecurved surface of the boiled egg with its eggshell removed, and apattern is drawn by the white egg white pattern layer against thebackground of the whole yolk skin layer; hence, the white patternagainst the simple background of a single color, yellow, is expressedstably so as to appear clearly, thereby providing a tasteful boiled egg.

As a third aspect of the present invention for solving theabove-mentioned problems, the invention set forth in claims 8 through 10is claimed.

The configuration of the invention set forth in claim 8 relates to astructure of a patterned boiled egg, wherein, as shown in FIG. 22, awhole egg white skin layer 21 a is formed of an egg white coagulatingalong the whole curved surface of the boiled egg, and a yolk pattern,layer 19 a is formed of a yolk coagulating so as to draw a patternagainst the background of the whole egg white skin layer 21 a whileeliminating the egg white near the curved surface inside the whole eggwhite skin layer 21 a.

The configuration of the invention set forth in claim 9 relates to amethod for producing the patterned boiled egg having the structure ofthe invention set forth in claim 8, comprising a first step, i.e., ayolk film tearing step for tearing the yolk film of an egg; a secondstep, i.e., a yolk positioning step, for positioning an uncoagulatedyolk after the tearing of the yolk film by floating the uncoagulatedyolk in the egg white inside the eggshell and by positioning theuncoagulated yolk so that the uncoagulated yolk makes contact with theinner face of the eggshell; a third step, i.e., a yolk film layerforming step, for forming a yolk pattern layer, corresponding to the eggwhite pattern layer obtained by the egg white pattern layer forming stepof claim 2, for the uncoagulated yolk, the film of which is torn; and afourth step, i.e., a whole egg white skin layer forming step for forminga whole egg white skin layer along the whole curved surface of the eggby boiling the egg, in which the yolk pattern layer is formed, whilerotating and rocking the egg around the major axis of the egg used asits rotating/rocking center axis in a state wherein the egg is partiallydipped in a heating medium, such as hot water, and by coagulating theuncoagulated egg white, which is relatively difficult to coagulate,sinking near the inner face of the lower portion of the eggshell dippedin the heating medium and attached to the eggshell, earlier than theuncoagulated yolk, which is relatively easy to coagulate, floating nearthe inner face of the upper portion of the eggshell not dipped in theheating medium and attached to the eggshell, during the rotation androcking, so that the uncoagulated egg white surrounds the yolk patternlayer attached to the inner face of the eggshell, makes contact with theyolk pattern layer and becomes the background of the yolk pattern layer.

The configuration of the invention set forth in claim 10 relates to theexecution of the yolk film tearing step in the method of producing thepatterned boiled egg set forth in claim 9 by using a rotating/stoppingyolk film tearing step similar to that set forth in claim 3.

In accordance with the configuration of the invention set forth inclaims 8 through 10 claimed as the above-mentioned third aspect, incomparison with the configuration of the invention set forth in claims 1through 7 claimed as the first and second aspects the color arrangementrelationship between the background and the pattern is reversed, thatis, a pattern of the yellow yolk pattern layer is drawn against thebackground of the white whole egg white skin layer disposed to cover thewhole of the curved surface, thereby providing unexpected enjoyment inthe reverse expression of the color arrangement of the background andthe pattern; in particular, tasteful boiled eggs are also provided inview of unexpected enjoyment from the combination of a pair of eggsidentical in pattern but reverse in the color arrangement with respectto the background and the pattern, that is, an egg having the structure(FIG. 16) of the invention set forth in claim 4 as the second aspect andan egg having the structure (FIG. 22) of the invention set forth inclaim 8 as this third aspect.

As a fourth aspect of the present invention for solving theabove-mentioned problems, the invention set forth in claims 11 through13 is claimed.

The configuration of the invention set forth in claim 11 relates to astructure of a patterned boiled egg, wherein, as shown in FIG. 26, ahalf egg white skin layer 9 b is formed of an egg white coagulatingalong nearly one half of the curved surface of the boiled egg, a yolkpattern layer 19 a is formed of a yolk coagulating so as to draw apattern against the background of the half egg white skin layer 9 bwhile eliminating the egg white near the curved surface inside the halfegg white skin layer 9 b, and a half yolk skin layer 9 a is formed of ayolk coagulating along nearly the other half of the curved surface.

The configuration of the invention set forth in claims 12 and 13 relatesto a method for producing the patterned boiled egg having the structureof the invention set forth in claim 11, comprising a first step, i.e., arotating/stopping yolk film tearing step for tearing the yolk film,similar to that set forth in claims 2 and 3 and used as a yolk filmtearing step; a second step, i.e., a yolk positioning step for floatingthe yolk in the egg white, similar to that set forth in claim 9 and usedas a yolk positioning step; a third step, i.e., a yolk pattern layerforming step for forming a yolk pattern layer, similar to that set forthin claim 9 and used as a yolk pattern layer forming step; a fourth step,i.e., a yolk/egg white positioning step, for positioning an uncoagulatedyolk by floating the uncoagulated yolk in the egg white inside theeggshell so that the uncoagulated yolk makes contact with nearly theother half of the inner face of the eggshell of the egg after the yolkpattern layer is formed and attached, and for positioning anuncoagulated egg white by sinking the uncoagulated egg white so that theuncoagulated egg white surrounds the yolk pattern layer attached tonearly one half of the inner face of the eggshell of the egg and makescontact therewith; a fifth step, i.e., a half egg white skin layerforming step, for forming a half egg white skin layer along nearly onehalf of the curved surface of the egg by boiling the egg, after thepositioning of the yolk and egg white, in its stationary posture as itis in a heating medium, such as hot water, and by coagulating theuncoagulated egg white so that the uncoagulated egg white sinks belowthe uncoagulated yolk floating inside the eggshell, surrounds the yolkpattern layer, makes contact with the yolk pattern layer and becomes thebackground of the yolk pattern layer; and a sixth step, i.e., a halfyolk skin layer forming step, for forming a half yolk skin layer alongnearly the other half of the curved surface of the egg by boiling theegg, after the positioning of the yolk and egg white, in its stationaryposture as it is in a heating medium, such as hot water, and bycoagulating the uncoagulated yolk floating in the egg white inside theeggshell.

In accordance with the configuration of the invention set forth inclaims 11 through 13 claimed as the above-mentioned fourth aspect, incomparison with the configuration of the invention set forth in claims 1through 7 claimed as the first and second aspects, the color arrangementrelationship between the background and the pattern is reversed, and thecurved surface is divided into nearly equal halves; that is, in thewhite half egg white skin layer disposed on nearly one half, a patternis drawn clearly by the yellow yolk pattern layer in two colors, and innearly the other half other than the white half egg white skin layer,the yellow half yolk skin layer is disposed, thereby providingunexpected enjoyment in the reverse expression of the color arrangementof the background and the pattern; in particular, tasteful boiled eggsare also provided in view of unexpected enjoyment from the combinationof a pair of eggs identical in pattern but reverse in the colorarrangement of the background and the pattern, that is, an egg havingthe structure (FIG. 9) of the invention set forth in claim 1 as thefirst aspect and an egg (FIG. 26) having the structure of the inventionset forth in claim 11 as this fourth aspect.

As a fifth aspect of the present invention for solving theabove-mentioned problems, the invention set forth in claims 14 through16 is claimed.

The configuration of the invention set forth in claim 14 relates to astructure of a patterned boiled egg, wherein, as shown in FIG. 30, ahalf egg white skin layer 9 b is formed of an egg white coagulatingalong nearly one half of the curved surface of the boiled egg, a yolkpattern layer 19 a is formed of a yolk coagulating so as to draw apattern against the background of the half egg white skin layer 9 bwhile eliminating the egg white near the curved surface inside the halfegg white skin layer 9 b, a half yolk skin layer 9 a is formed of a yolkcoagulating along nearly the other half of the curved surface of theboiled egg, and an egg white pattern layer 3 e is formed of an egg whitecoagulating so as to draw a pattern against the background of the halfyolk skin layer while eliminating the yolk near the curved surfaceinside the half yolk skin layer 9 a.

The configuration of the invention set forth in claims 15 and 16 relatesto a method for producing the patterned boiled egg having the structureof the invention set forth in claim 14, comprising a first step, i.e., arotating/stopping yolk film tearing step, similar to that of theinvention set forth in claims 12 and 13 and used as a yolk film tearingstep; a second step, i.e., a yolk positioning step, similar to that ofthe invention set forth in claim 12; a third step, i.e., a yolk patternlayer forming step, similar to that of the invention set forth in claim12; a fourth step, i.e., an egg white pattern layer forming step,carried out simultaneously with or before or after this, for forming anegg white pattern layer by heating a specific pattern area drawn onnearly the other half of the curved surface area-selectively andconcentrically, and by coagulating the uncoagulated egg white on theinner face of the eggshell so that the uncoagulated egg white removablyattaches to the inner face of the eggshell and draws a pattern; and afifth step, i.e., a yolk/egg white positioning step; and a sixth step,i.e., a half egg white skin layer forming step and a seventh step, i.e.,a half yolk skin layer forming step, similar to those of the inventionset forth in claim 12, respectively; the production method is completedby these subsequent steps.

In accordance with the configuration of the invention set forth inclaims 14 through 16 claimed as the above-mentioned fifth aspect, thecurved surface is divided into nearly equal halves, and in the whitehalf egg white skin layer disposed on nearly one half, a pattern isdrawn clearly by the yellow yolk pattern layer in two colors, and in thehalf yellow yolk skin layer disposed in nearly the other half other thanthe white half egg white skin layer, another pattern is drawn clearly bythe white egg white pattern layer in two colors, reversed in colorarrangement with respect to the egg white pattern layer; hence,regarding the background and the pattern evaluated in accordance withthe relationship between an egg (FIG. 26) of the invention set forth inclaim 11 as the fourth aspect and an egg (FIG. 9) of the invention setforth in claim 1 as the first aspect, the unexpected enjoyment in thecombination of patterns, identical in patterns but reverse in colorarrangement, is united on the curved surface of one boiled egg, therebyproviding a tasteful boiled egg.

Generally, the configuration of the invention set forth in all theclaims as the above-mentioned first to fifth aspects provides anornamental expression by forming patterns in two colors, white andyellow, on the curved surface of a boiled egg in a state with itseggshell removed, by using only the yolk and egg white, the originalcontents inside the eggshell, as materials and by only selectivelyapplying heat and acceleration, without providing any mechanical processfor the eggshell and without introducing any materials into the eggshellfrom outside the eggshell; hence, two trade-off requests, i.e., theremoval of anxiety in food hygiene control and the improvement intastefulness on the dining table, are fulfilled, whereby thesatisfaction of consumers with respect to tastefulness on the diningtable is improved.

BRIEF EXPLANATION OF DRAWINGS

FIG. 1 through FIG. 9 relate to the first aspect of the invention.

FIGS. 1(A) through (D) are explanatory views showing the configurationand production process of an induction heating pattern sheet for ayolk/egg white pattern layer forming step.

FIG. 2 relates to an induction heating apparatus for an egg whitepattern layer forming step in accordance with the invention set forth inclaim 2; FIG. 2(A) is a plan view of the main portion of the inductionheating apparatus loaded with an egg to which the induction heatingpattern sheet is attached, and FIG. 2(B) is a partially sectional sideview of the main portion.

FIG. 3 is a sectional view of an egg to which the induction heatingpattern sheet shown in FIG. 2 is attached.

FIG. 4 is an external perspective view showing the configuration of ayolk film tearing apparatus for a yolk film tearing step in accordancewith the invention set forth in claims 2 and 3.

FIG. 5 is a sectional view of an egg after the yolk film tearing step.

FIG. 6 is a sectional view of an egg in a horizontal stationary posture.

FIG. 7 is a sectional view showing the configuration of a horizontalstationary egg boiling apparatus for a half yolk skin layer forming stepand a half egg white skin layer forming step set forth in claim 2.

FIG. 8 shows the configuration of an egg holder in the stationary eggboiling apparatus of FIG. 6; FIG. 8(A) is an extracted plan view of themain portion thereof, and FIG. 8 (B) is an extracted side view of themain portion thereof.

FIG. 9 shows the structure of a patterned boiled egg in accordance withthe invention set forth in claim 1; FIG. 9(A) is a front view of the eggwith its eggshell removed, FIG. 9 (B) is a side view thereof, FIG. 9(C)is a perspective view of the egg with its eggshell partially removed,and FIG. 9(D) is a partially sectional perspective view thereof.

FIG. 10 through FIG. 17 relate to the second aspect of the invention.

FIG. 10 shows the configuration of a horizontal rotation heatingapparatus for a central portion yolk skin layer forming step inaccordance with the invention set forth in claim 6;

FIG. 10(A) is a front sectional view thereof, and FIG. 10(B) is a sidesectional view thereof.

FIG. 11 shows the configuration of an inclined rotation heatingapparatus for an acute end portion yolk skin layer forming step inaccordance with the invention set forth in claim 6; FIG. 11(A) is afront view thereof, and FIG. 11(B) is a side sectional view thereof.

FIG. 12 is a front sectional view showing the configuration of avertical stationary egg boiling apparatus for an obtuse end portion yolkskin layer forming step in accordance with the invention set forth inclaim 6.

FIG. 13 is a sectional view of a boiled egg supported by an egg holderin the vertical stationary egg boiling apparatus of FIG. 12.

FIG. 14 shows the configuration of a whole dipping rotating/rocking eggboiling apparatus for a rotating/rocking whole yolk skin layer formingstep in accordance with the invention set forth in claim 7; FIG. 14(A)is a plan view thereof, and FIG. 14(B) is a front sectional viewthereof.

FIGS. 15(A), (B) and (C) are explanatory views for illustrating theoperation of a whole yolk skin layer forming step in time series in thewhole dipping rotating/rocking egg boiling apparatus of FIG. 14.

FIG. 16 shows the structure of a patterned boiled egg in accordance withthe invention set forth in claim 4; FIG. 16(A) is a front view of theegg with its eggshell partially removed, and FIG. 16(B) is a partiallysectional perspective view of the egg of FIG. 16(A).

FIG. 17 shows the structure of a modified example of the patternedboiled egg of FIG. 16.

FIG. 18 through FIG. 22 relate to the third aspect of the invention.

FIG. 18 is a side sectional view of the main portion of the inductionheating apparatus loaded with an egg to which the induction heatingpattern sheet for a yolk pattern layer forming step set forth in claim 9is attached.

FIG. 19 is a sectional view showing the extracted configuration of anegg loaded in the induction heating apparatus of FIG. 18.

FIG. 20 is a front sectional view showing the configuration of a partialdipping rotating/rocking egg boiling apparatus for a whole egg whiteskin layer forming step in accordance with the invention set forth inclaim 9.

FIGS. 21(A), (B) and (C) are explanatory views for illustrating theoperation of the whole egg white skin layer forming step in time seriesin the partial dipping rotating/rocking egg boiling apparatus of FIG.20.

FIG. 22 shows the structure of a patterned boiled egg in accordance withthe invention set forth in claim 8; FIG. 22(A) is a front view of theegg with its eggshell partially removed, and FIG. 22(B) is a partiallysectional perspective view of the egg of FIG. 22(A).

FIG. 23 through FIG. 26 relate to the fourth aspect of the invention.

FIG. 23 is a side sectional view of the main portion of the inductionheating apparatus loaded with an egg to which the induction heatingpattern sheet for a yolk pattern layer forming step set forth in claim12 is attached.

FIG. 24 is a sectional view showing the extracted configuration of anegg loaded in the induction heating apparatus of FIG. 23.

FIG. 25 is an extracted sectional view showing an egg in a yolk/eggwhite positioning step in accordance with the invention set forth inclaim 12.

FIG. 26 is a side view showing the structure of a patterned boiled eggin accordance with the invention set forth in claim 11.

FIG. 27 through FIG. 30 relate to the fifth aspect of the invention.

FIG. 27 is a side sectional view of the main portion of the inductionheating apparatus loaded with an egg to which the induction heatingpattern sheets for a yolk pattern layer forming step and an egg whitepattern layer forming step set forth in claim 15 are attached.

FIG. 28 is a sectional view showing the extracted configuration of anegg loaded in the induction heating apparatus of FIG. 27.

FIG. 29 is an extracted sectional view showing an egg in a yolk/eggwhite positioning step in accordance with the invention set forth inclaim 15.

FIG. 30 is a side view showing the structure of a patterned boiled eggin accordance with the invention set forth in claim 15.

FIG. 31 and FIG. 32 relate to the prior art; FIG. 31 is a perspectiveview of an area-selective heating apparatus replaceable with theinduction heating apparatus, and FIG. 32 is an explanatory view of ayolk film tearing apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

The best mode for embodying the invention set forth in claims 1 through3 will be described below as the first aspect of the present inventionreferring to FIG. 1 through FIG. 9. Before an egg white pattern layerforming step for attaching an egg white pattern layer formed of an eggwhite coagulating on the curved surface of an egg or a yolk patternlayer forming step for attaching a yolk pattern layer formed of acoagulating yolk in a similar way to the inner face of the eggshell byarea-selectively heating the eggshell externally, an induction heatingpattern sheet required for area-selective heating on the surface of theeggshell by using an induction heating apparatus is produced. As shownin FIG. 1(A), a guide pattern 1 b assumed to be a pattern in the end onthe curved surface of a boiled egg is drawn on a base sheet 1 a made ofpaper by an appropriate method such as printing. This kind of base sheet1 a is placed on an integrated magnetic block 1 c having an identicalmagnetic pole configuration as shown in FIG. 1(B), and inductedparticles 1 d of a magnetic material are magnetized on the guide patternguided by the guide pattern 1 b on the sheet, thereby attracted andfixed; hence, a character “Kotobuki” is drawn by a collection of theinducted particles 1 d in the case of the example shown in the figure.For example, segments obtained by cutting a mini-rope (trade name, madeby Toyo Mini-Rope Co., Ltd.) commercially available as a 0.12 mmdiameter steel wire rope comprising a bundle of 0.03 mm diameter elementwires to a length of about 5 mm can be used properly as the inductedparticles 1 d of the magnetic material. Next, commercially availablesilicone rubber, for example, TSE3504 silicone rubber (made by ToshibaSilicone Co., Ltd.), is poured over the collection of the inductedparticles 1 d on the base sheet 1 a within the range of the base sheet 1a in an open state; as shown in FIGS. 1(C) and 1(D), an inductionheating pattern sheet 2 is formed on the guide sheet 1 a to enclose thecollection of the inducted particles id for drawing the guide patternand to have a contour suited for attachment to the outer surface of theeggshell. The induction heating pattern sheet 2 formed in this way isremoved from the guide sheet 1 a and is attached to an appropriateposition on the surface of the eggshell.

An egg 3, to which the induction heating pattern sheet 2 is attached, isloaded in a heating chamber surrounded by the induction coil 2 a of anordinary induction heating apparatus as shown in FIG. 2(A). As aninduction heating apparatus for this purpose, for example, acommercially available induction heating furnace MU-1700B (made bySekisui Electronics Co., Ltd.) can be used properly; in a typical case,induction heating is carried out at a setting temperature of 150° C. andfor a duration of 10 to 20 seconds by this heating furnace (450 kHz, 350W). In the case of the example shown in the figure, as shown in FIG.2(B), the induction heating pattern sheet 2 is attached to the upperportion of the eggshell of the egg 3, which is mounted in a horizontalattitude on a heating mount base 2 b made of a non-conductive materialso that the acute end portion 3 a is positioned on the left side and theobtuse end portion 3 b is positioned on the right side in the figure. Inthis state, for example, when the egg white pattern layer forming stepstarts and when high-frequency electric power is supplied to theinduction coil 2 a of the induction heating apparatus, by inducted eddycurrent inducted in the collection of the inducted particles id insidethe induction heating pattern sheet 2 attached to the surface of theeggshell of the egg 3, the collection is heated, and the surfacetemperature of the eggshell is maintained at about 150° C.; hence, thearea on the outer surface of the eggshell of the egg 3, corresponding tothe area of the pattern drawn by the collection, is heatedarea-selectively and concentrically. In the egg 3 heatedarea-selectively and concentrically, the egg white 3 c positioned on theperipheral portion confronts the inner face of the eggshell 3 d as shownin FIG. 3; by the area-selective and concentric heating via the eggshell3 d, an egg white pattern layer 3 e having a thickness of about 1 mm isformed on the outer surface of the egg white, and the egg white patternlayer is removably attached to the corresponding inner face of the upperportion of the eggshell 3 d. In this stage, an uncoagulated yolk 3 genclosed with a strong yolk film 3 f is surrounded by the uncoagulatedegg white 3 c and floats at the center portion. The major axis 3 h ofthe egg 3 is an axis of connection from the acute end portion 3 a on theleft side in the figure and the obtuse end portion 3 b on the right sidein the figure.

In the next yolk film tearing step, the egg 3 after the formation of theegg white pattern layer is held in a yolk film tearing apparatus 4 by anappropriate ordinary holding mechanism 4 a as shown in FIG. 4. In theyolk film tearing apparatus 4, a motor 4 c for rotating its rotationshaft 4 b at high speed is integrally assembled with a brake 4 d forimmediately stopping the rotation shaft 4 b during its rotation; theholding mechanism 4 a is provided at one end of the rotation shaft 4 b.The commercially available BNPCF-J-0.4 type Motor Unit (made by HitachiLtd.) is suitably usable as the integrated structure of the motor 4 cand the brake 4 d. The egg 3 held with the holding mechanism 4 a isrotated for about 3 seconds at a rotation speed of about 3,6000 rpmaround the major axis 3 h used as its rotation center axis via therotation shaft 4 b rotated by the motor 4 c, and during this rotation,the brake 4 d is applied and the rotation is stopped immediately. At thetime of the immediate stop at each of the several repetitions of thisintermittent operation of high-speed rotation and immediate stop, ashearing force owing to the difference between the inertial force actingon the yolk 3 g at the central portion in the eggshell 3 d and theinertial force acting on the egg white 3 c at the peripheral portionapplies to the yolk film 3 f, thereby tearing the yolk film. After theyolk film 3 f is torn, since the specific gravity of the uncoagulatedyolk 3 g is relatively smaller than that of the egg white 3 c, theuncoagulated yolk 3 g floats in the uncoagulated egg white 3 c and movesupward inside the eggshell 3 d as shown in FIG. 5. In the following yolkpositioning step, the egg 3 is positioned so that the uncoagulated yolk3 g floating in the egg white 3 c inside the eggshell 3 d makes contactwith the egg white pattern layer 3 e attached to the inner face of theeggshell 3 d; in the example shown in FIG. 6, the egg 3 is positioned ina horizontal stationary posture so that the major axis 3 h of the egg 3becomes nearly horizontal and so that the egg white pattern layer 3 e islocated upward. As a result, as shown in FIG. 6, the uncoagulated yolk 3g floating in the uncoagulated egg white 3 c makes contact with the eggwhite pattern layer 3 e attached to the inner face of the upper portionof the eggshell 3 d.

In the following half yolk skin layer forming step and the followinghalf egg white skin layer forming step, as shown in FIG. 7, the eggs 3positioned in the horizontal stationary posture are boiled in hot waterused as a heating medium by a stationary egg boiling apparatus 7. Thestationary egg boiling apparatus 7 shown in FIG. 7 is provided with aboiling bath 7 b assembled on an ordinary heater 7 a, such as a gasburner, and an egg holder 7 c is installed inside the boiling bath 7 b;the eggs 3 arranged in several rows and several columns are held by theegg holder 7 c in the horizontal stationary posture as shown in FIG. 6,and dipped in the hot water 7 d inside the boiling bath 7 b andaccommodated therein. In this case, the egg holder 7 c may have astructure shown in FIGS. 8(A) and 8(B), wherein the lower portion of theegg 3 is fitted between a pair of beams 7 e and 7 e disposedorthogonally to the major axis 3 h of the egg 3 and horizontally with aclearance slightly smaller than the length of the minor axis 3 i of theegg 3, for measuring the maximum dimension between two confrontingeggshells 3 d and 3 d, in the horizontal stationary posture so that themajor axis 3 h is in parallel with the longitudinal direction of thebeams.

When the half yolk skin layer forming step and the half egg white skinlayer forming step start, the heater 7 a operates and continuously heatsthe hot water 7 d inside the boiling bath 7 b; the eggs 3 positioned anddipped in the horizontal stationary posture therein are usually boiledat about 80° C. for about 15 minutes. By this boiling, the uncoagulatedyolk 3 g floating in the egg white 3 c inside the eggshell 3 d surroundsthe egg white pattern layer 3 e and makes contact with the egg whitepattern layer and then coagulates so as to become the background of theegg white pattern layer; hence, as shown in FIGS. 9(A) and 9(B), a halfyolk skin layer 9 a is formed along nearly one half of the curvedsurface of the egg; on the other hand, the egg white 3 c sinking belowthe uncoagulated yolk 3 g floating inside the eggshell 3 d coagulates,whereby a half egg white skin layer 9 b is formed along nearly the otherhalf of the curved surface of the egg.

FIG. 9(C) is a perspective view showing the structure of a patternedboiled egg produced by the above serial production steps, with theeggshell 3 d partially removed, and FIG. 9(D) is a similar partiallysectional perspective view of this. In these figures, the half yolk skinlayer 9 a is formed by the yolk 3 g coagulating along at least nearlyone half of the curved surface of the boiled egg 9, thereby having asufficient depth toward the central portion; the egg white pattern layer3 e is formed by the egg white 3 c coagulating so as to draw a patternagainst the background of the half yolk skin layer 9 a while eliminatingthe yolk 9 a near the curved surface inside the half yolk skin layer 9a, thereby having a slight depth toward the central portion; the halfegg white skin layer 9 b is formed by the egg white 3 c coagulatingalong at least nearly the other half of the curved surface of the boiledegg 9, thereby having a sufficient depth toward the central portion.Next, the best mode for embodying the present invention set forth inclaims 4 through 7 will be described below as the second aspect of thepresent invention referring to FIG. 10 through FIG. 17. An egg whitepattern layer forming step to be carried out first is the same as theegg white pattern layer forming step described referring to FIG. 1through FIG. 3 as the best mode for carrying out the first aspect of theinvention, and the following yolk film tearing step is also the same asthe yolk film tearing step described referring to FIG. 4 and FIG. 5.

As the following whole yolk skin layer forming step, two examples, thatis, a first embodiment described referring to FIG. 10 through FIG. 13and a second embodiment described referring to FIG. 14 and FIG. 15, areproposed herein.

In the first embodiment, first, a central portion yolk skin layerforming step is carried out; in this step, as shown in FIG. 10, the egg3 after the formation of the egg white pattern layer is loaded in ahorizontal rotation heating apparatus 10. In the horizontal rotationheating apparatus 10, a motor 10 c is installed on a frame 10 b forpartitioning a heating chamber 10 a; an output rotation shaft 10 eextending outside the motor 10 c via an appropriate reduction gear 10 dfrom the motor 10 c is installed horizontally between a pair of opposedframes 10 b and 10 b; the tip of the output rotation shaft 10 e; isrotatably supported by a bearing 10 f on the opposed frame 10 b; acylindrical roller log is fitted on the output rotation shaft; in theheating chamber 10 a above the cylindrical roller, the egg 3 is placedon the cylindrical roller 10 g in a horizontal rotation attitude so thatthe major axis 3 h is in parallel with the output rotation shaft 10 e,whereby the egg 3 is loaded inside the heating chamber 10 a. Near theframe 10 b, a column 10 h is disposed vertically, and a heating blower10 j is supported by a support arm 10 i extending above the heatingchamber 10 a from the column, and the nozzle 10 k of the heating blower10 j faces the upper portion of the egg 3 loaded inside the heatingchamber 10 a. When the central portion yolk skin layer forming stepstarts, the heating blower 10 j operates to blow hot air of about 150°C. from the nozzle 10 k to the upper portion of the egg 3; at the sametime, the motor 10 d also operates to rotate the cylindrical roller 10 gvia the rotation of the output rotation shaft 10 f at a low speedcounterclockwise as shown in FIG. 10(B). Then, the outer circumferenceof the egg 3 placed on the outer circumference of the rotatingcylindrical roller 10 g in a horizontal rotation attitude so as to makefrictional contact with the outer circumference of the cylindricalroller 10 g is fed by a friction force, and the egg 3 is rotated aroundthe major axis 3 h used as its horizontal rotation center axis at a lowspeed of one rotation in 4 minutes clockwise as shown in the figure. Inthe egg 3 rotating horizontally at a low speed clockwise as shown inFIG. 10(B) as described above, the uncoagulated yolk 3 g, the film ofwhich is torn, floats in the uncoagulated egg white 3 c sinkingdownward, and gathers directly below the upper portion of the eggshell 3d; in the uncoagulated yolk 3 g gathering here, the portion of theuncoagulated yolk 3 g near the inner face of the eggshell 3 d, exposedto the hot air blown from the heating blower 10 j via the nozzle 10 k,starts coagulating, and a coagulation start area 3 ga is formed thereand gradually changes to a completely coagulated area 3 gb with thepassage of time of the exposure to the hot air, and the coagulated areaitself advances gradually clockwise as shown in FIG. 10(B) with thepassage of time. As the number of the horizontal rotations of the egg 3increases, the coagulation of the uncoagulated yolk 3 g along the curvedsurface at the portion near the central portion of the curved surface ofthe egg 3 along the major axis 3 h advances, whereby a central portionyolk skin layer 3 gc is formed soon.

In the case when the egg white pattern layer 3 e formed by the precedingegg white pattern layer forming step is attached to the inner face ofthe eggshell 3 d in the area wherein the central portion yolk skin layer3 gc is formed, the central portion yolk skin layer 3 gc is formed so asto surround the egg white pattern layer 3 e and make contact with theegg white pattern layer, thereby becoming the background of the eggwhite pattern layer.

Next, in an acute end portion yolk skin layer forming step, the egg 3subjected to the above-mentioned central portion yolk skin layer formingstep is loaded in an inclined rotation heating apparatus 11 shown inFIG. 11. In the inclined rotation heating apparatus 11, an inclinedframe 11 b for partitioning an inclined heating chamber 11 a isinstalled on an inclined base 11 ba; a bearing 11 f is securelyinstalled on the inclined frame 11 b secured to the installation face ofthe inclined base 11 ba; a motor 11 c is installed on the opposed upperinclined frame 11 b; an output rotation shaft 11 e extending outside themotor 11 c via an appropriate reduction gear 11 d from the motor 11 c isinstalled horizontally between a pair of inclined frames 11 b and 11 b;an inclined cylindrical roller 11 g is fitted on the output rotationshaft; in the inclined heating chamber 11 a disposed at the upper rightof the inclined cylindrical roller in the figure, the egg 3 is loaded inthe inclined heating chamber 11 a by placing the egg on the inclinedcylindrical roller 11 g in an inclined rotation attitude so that themajor axis 3 h is in parallel with the output rotation shaft 11 e; inthis case, the egg is loaded in an inclined attitude wherein the acuteend portion 3 a of the egg 3 faces the upper left in the figure and theobtuse end portion 3 b is supported by the inclined face of the inclinedbase 11 ba. The configuration wherein the nozzle 11 k of a heatingblower 11 j supported by a column 11 b and a support arm 11 i faces theegg 3 is the same as that shown in FIG. 10; however, in this case, hotair from the nozzle 11 k disposed at a predetermined inclined angle withrespect to the major axis 3 h of the egg 3 is blown to the acute endportion 3 a of the egg 3. When the acute end portion yolk skin layerforming step starts, the acute end portion 3 a of the egg 3 is rotatedin an inclined state at low speed in a heating environment by hot air ofabout 150° C., just as in the case shown in FIG. 10. Then, theuncoagulated yolk 3 g floating directly below the eggshell 3 d at theacute end portion 3 a of the egg 3 forms a coagulating area, and thecoagulating area expands as the number of inclined rotations increases;an acute end portion yolk skin layer 3 gd is soon formed so as toconnect the formed central portion yolk skin layer 3 gc with the acuteend portion 3 a of the egg 3.

In the following obtuse end portion yolk skin layer forming step, theegg 3 subjected to the above-mentioned acute end portion yolk skin layerforming step is loaded in a vertical stationary egg boiling apparatus 12shown in FIG. 12. The vertical stationary egg boiling apparatus 12 isthe same as the horizontal stationary egg boiling apparatus 7 shown inFIG. 7 in the basic configuration and provided with a heater 12 a, aboiling bath 12 b and an egg holder 12 c; the eggs 3 are accommodated inthe boiling bath 12 b so as to be dipped in hot water 12 d continuouslyheated by the heater 12 a. In the case of the horizontal stationary eggboiling apparatus 7 shown in FIG. 7, the eggs 3 are maintained in ahorizontal stationary posture by the holder 7 c so that the major axes 3h of the eggs 3 are horizontal; however, in the case of the verticalstationary egg boiling apparatus 12 shown in FIG. 12, the eggs 3 aremaintained in a vertical stationary posture by the holder 12 c so thatthe major axes 3 h of the eggs 3 are vertical and so that the obtuse endportions 3 b of the eggs 3 face upward.

For this purpose, as shown in FIG. 13, the acute end portion 3 a of theegg 3 is fitted in a concave portion 12 ca generally formed to have aconical shape at the bottom portion of the holder 12 c for the egg 3.When the obtuse end portion yolk skin layer forming step starts, the egg3 is boiled, just as in the apparatus shown in FIG. 7. Hence, as shownin FIG. 13, the uncoagulated yolk 3 c floating in the uncoagulated eggwhite 3 c and gathering near the obtuse end portion 3 b of the egg 3 inthe above-mentioned vertical stationary posture coagulates, whereby anobtuse end portion yolk skin layer 3 ge is formed so as to be connectedto the formed central portion yolk skin layer 3 gc at the obtuse endportion 3 b at the upper position of the egg 3. This completes the firstembodiment of the whole yolk skin layer forming step.

Next, in the second embodiment of the whole yolk skin layer formingstep, a complete dipping rotating/rocking egg boiling apparatus 14 shownin FIG. 14 is the same as the apparatus shown in FIG. 7 in the basicconfiguration, except that a rotating/rocking disc for rotating the eggs3 immediately after the eggs 3 are subjected to the yolk film tearingstep is included instead of the holder for the eggs 3; the apparatus isprovided with a heater 14 a, a boiling bath 14 b and a rotating/rockingdisc 14 c; the eggs 3 are accommodated in the boiling bath 14 b so as tobe wholly dipped in hot water 14 d heated continuously by the heater 14a. However, in the apparatus shown in FIG. 14, rotation operation androcking operation are provided for the eggs 3 in the hot water 14 insidethe boiling bath 14 b.

For this purpose, the rotating/rocking disc 14 c having a disc-likeshape is installed on the reduction output rotation shaft 14 ca of anappropriate rotation drive apparatus, such as a motor, not shown, in anattitude so as to cover the circular bottom face of the boiling bath 14b as shown in FIG. 14(A). The rotating/rocking disc 14 c is providedwith belt-like concave step portions 14 cb radially extending from thecenter of the reduction output rotation shaft 14 ca, the width of whichis close to the dimension of the minor axis of the egg 3; at theremaining portion of the rotating/rocking disc 14 c, bulging stepportions 14 cc, projecting with respect to the concave step portions 14cb, are formed; hence, the concave step portions 14 cb and the bulgingstep portions 14 cc are arranged so as to be disposed alternately alongthe circumferential direction of the rotating/rocking disc 14 c. In therotating/rocking whole yolk skin layer forming step, in a state of beingdipped completely in the hot water 14 d maintained at about 70° C.inside the boiling bath 14 b, the eggs 3 are rocked and rolled on therotating/rocking disc 14 c rotating at a low speed of about 10 rpm,whereby the eggs 3 are boiled for about 15 minutes while being subjectedto rotation mainly around the major axis 3 h of the egg 3 used as itsrotation center axis and to rocking mainly around the minor axis 3 i ofthe egg 3 used as its rocking center axis. FIG. 15 is a schematicexplanatory view illustrating a time-series progress of actions to theegg 3 in the whole yolk skin layer forming step. In the first stageshown in FIG. 15(A), the uncoagulated yolk 3 g floating in the egg white3 c inside the eggshell 3 d and gathering at the upper portion owing toits low specific gravity in comparison with the egg white tends tocoagulate easily at a low temperature in comparison with the egg white 3c and is sufficiently heated by the hot water 14 d in a completelydipped state, whereby the coagulation start area 3 ga of the yolk 3 g isformed at the upper portion in an early stage, and the area 3 ga isattached to the upper portion of the eggshell 3 d. As the egg 3 havingthe coagulation start area 3 ga of the yolk at the upper portion ismoved to the middle left of FIG. 15(A) by the rotation of therotating/rocking disc 14 c itself, the egg 3 is rocked in the hot water,shoved so as to rise to the bulging step portion 14 cc and rollsclockwise in the figure, thereby causing rotation reacted by themovement of the rotating/rocking disc 14 c; hence, the coagulation startarea 3 ga of the yolk is rotated clockwise in the figure and moved,thereby gradually changing to the completely coagulated area 3 gb. Atthat time, in an area wherein the yolk 3 g changes to the completelycoagulated area 3 gb to become the whole yolk skin layer 3 gf, in thecase when the egg white pattern layer 3 e formed by the preceding eggwhite pattern layer forming step has been attached to the inner face ofthe eggshell 3 d, the whole yolk skin layer 3 gf is formed so as tosurround the egg white pattern layer 3 e, make contact with the eggwhite pattern layer and become the background of the egg white patternlayer. When the rotation of the rotating/rocking disc 14 c proceedsfurther, the egg 3 is rocked and shoved so as to fall from the bulgingstep portion 14 cc to the concave step portion 14 cb as shown in FIG.15(B), thereby causing rotation owing to reaction in the clockwisedirection in the figure; hence, the completely coagulated area 3 gbturns and enters the lower portion; by this amount, the uncoagulatedyolk 3 g newly makes contact with the inner face of the upper portion ofthe eggshell 3 d, thereby newly forming the coagulation start area 3 ga.When the rotation of the rotating/rocking disc 14 c proceeds further,the egg 3, while being rocked again, ejected from the concave stepportion 14 cb and shoved so as to rise to the bulging step portion 14cc, further continues clockwise rotation owing to reaction as shown inFIG. 15 C; hence, the tip portion of the completely coagulated area 3 gbformed at the first stage shown in FIG. 15(A) in the rotation directionof the egg 3 is connected to the completely coagulated area 3 gb formedat the latest stage; hence, the whole yolk skin layer is formed, and theuncoagulated egg white 3 e that is difficult to coagulate at lowtemperature in comparison with the yolk 3 g is surrounded at the centralportion. After waiting for the coagulation of the egg white 3 e at thecentral portion, proceeding with a delay, the whole yolk skin layerforming step is completed.

FIG. 16(A) is a front view showing the structure of a patterned boiledegg produced by the serial production steps including those inaccordance with the first and second embodiments for forming theabove-mentioned whole yolk skin layer forming structure, in a state withthe eggshell partially removed; FIG. 16(B) is a partially sectionalperspective view thereof. In the figures, the whole yolk skin layer 3 gfis formed by the yolk 3 g coagulating along the whole curved surface ofthe boiled egg and has a sufficient depth toward the central portion;the egg white pattern layer 3 e is formed by the egg white 3 ccoagulating so as to draw a pattern against the background of the wholeyolk skin layer 3 gf by eliminating the yolk near the curved surface ofthe whole yolk skin layer 3 gf, and has a slight depth toward thecentral portion. FIGS. 17(A) and (B), corresponding to FIGS. 16(A) and(B) with respect to drawing methods, show the structure of a boiled egghaving only the whole yolk skin layer 3 gf but not having the egg whitepattern layer 3 e. The boiled egg having this structure can be producedeventually by carrying out a process in which only the egg white patternforming step, i.e., the first step, is eliminated from the serialproduction steps in accordance with the invention set forth in claim 5;this boiled egg should be referred to as an “unpatterned reversed boiledegg.”

Next, the best mode for embodying the invention set forth in claims 8through 10 will be described below as the third aspect of the presentinvention referring to FIG. 18 through FIG.22. In the third aspect ofthe present invention, a yolk film tearing step is carried out as thefirst production step, and this step itself is the same as thatdescribed referring to FIG. 4 and FIG. 5 with respect to the firstaspect. In the following yolk positioning step, the induction heatingpattern sheet 2 is attached to a desired position on the outer surfaceof the eggshell 3 d of the egg 3 in preparation for the yolk patternlayer forming step, i.e., the next step; at that time, the egg 3 ispositioned in an attitude wherein the eggshell 3 d to which theinduction heating pattern sheet 2 is attached becomes the upper face,and loaded in a heating chamber surrounded by the induction coil 2 a ofan induction heating apparatus; whereby, as shown in FIG. 19, theuncoagulated yolk 3 g after the yolk film tearing step floats in theuncoagulated egg white 3 c inside the eggshell 3 d and makes contactwith the inner face of the eggshell 3 d. As shown in FIG. 18, the yolkpattern forming step, i.e., the next step, is carried out for the egg 3in the heating chamber surrounded by the induction coil 2 a; however,the heating itself at this step is the same as that of the egg whitepattern forming step described with respect to the first aspect of thepresent invention referring to FIG. 1 through FIG. 3, but ischaracterized in that the positional relationship between the egg whiteand yolk is reversed vertically by the preceding yolk positioning step.As a result of this yolk pattern layer forming step, as shown in FIG.19, the yolk pattern layer 19 a formed by the coagulation of theuncoagulated yolk 3 d is removably attached to the inner face of theupper portion of the eggshell 3 d. In the following whole egg white skinlayer forming step, the egg 3 is loaded in a partial dippingrotating/rocking egg boiling apparatus 14; the rotating/rocking eggboiling apparatus 14 itself used at this step is the same as thatdescribed with respect to the first aspect of the present inventionreferring to FIG. 14. However, in this step, unlike the state shown inFIG. 14, the egg 3 is not wholly dipped in hot water 14 d, but the egg 3is partially dipped in the hot water 14 d as shown in FIG. 20, andboiling is carried out in this state; preferably, the boiling is carriedout for about 15 minutes on the rotating/rocking disc 14 c rotating at alow speed of about 0.5 rpm in a state wherein about a 60% portion in theminor axis dimension of the egg 3 is dipped in the hot water 14 dmaintained at about 90° C.

FIG. 21 is a schematic explanatory view illustrating a time-seriesprogress of actions to the egg 3 in the whole egg white skin layerforming step. In the first stage shown in FIG. 21(A), the uncoagulatedyolk 3 g floating in the egg white 3 c and gathering at the upperportion is exposed outside the surface of the hot water 14 d and remainsin an uncoagulated state because of insufficient heat reception from thehot water 14 d; on the other hand, the uncoagulated egg white 3 c, whichtends to be coagulated with difficulty by heating in comparison with theyolk 3 d, sinks downward in the eggshell 3 d and sufficiently receivesheat from around the hot water 14 d in which the uncoagulated egg whiteis dipped; hence, the peripheral portion of the sunk uncoagulated eggwhite 3 c gradually changes to the coagulated area 21 a of the egg white3 c as the process proceeds, thereby growing to the whole egg white skinlayer 21 a soon. In the above-mentioned process of the growing of thewhole egg white skin layer 21 a, in the case when the yolk pattern layer19 a formed by the preceding yolk pattern layer forming step is attachedto the inner face of the eggshell 3 d in the area beyond that, the wholeegg white skin layer 21 a is formed so as to become the background ofthe yolk pattern layer 19 a. When the rotation of the rotating/rockingdisc 14 c proceeds further, as shown in FIG. 21(B), the egg 3 is rockedand shoved so as to fall from the bulging step portion 14 cc to theconcave step portion 14 cb, and the egg 3 rolls clockwise in the figureby reaction from the leftward movement of the rotating/rocking disc 14c; hence, the coagulated area 21 a of the egg white 3 c formed earlieris exposed outside the hot water 14 d; by that amount, the coagulatedarea 21 a of the egg white 3 c is newly formed near the inner face ofthe eggshell 3 d that has become dipped newly in the hot water 14 d.When the rotation of the rotating/rocking disc 14 c proceeds further, asshown in FIG. 21(C), the coagulated area 21 a of the egg white 3 cformed in the first stage shown in FIG. 21(A) is connected to thecoagulated area 21 a of the egg white 3 c formed most recent, and thethickness of the area 21 a increases; hence, the whole egg white skinlayer 21 a is formed, and the yolk 3 g that is easy to coagulate at lowtemperature in comparison with the egg white 3 c is surrounded therebyat the central portion while remaining uncoagulated. After waiting forthe coagulation of the yolk, proceeding with a delay, the whole eggwhite skin layer forming step is completed.

FIG. 22(A) is a front view showing the structure of a patterned boiledegg produced by the serial production steps described above, in a statewith the eggshell partially removed; FIG. 22(B) is a partially sectionalperspective view thereof. In the figures, the whole egg white skin layer21 a is formed by the egg white 3 c coagulated along the whole curvedsurface of the boiled egg and has a sufficient depth toward the centralportion; the yolk pattern layer 19 a is formed by the yolk 3 gcoagulating so as to draw a pattern against the background of the wholeegg white skin layer 21 a by eliminating the egg white near the curvedsurface of the whole egg white skin layer 21 a, and has a slight depthtoward the central portion.

Next, the best mode for embodying the present invention set forth inclaims 11 through 13 will be described below as the fourth aspect of thepresent invention referring to FIG. 23 through FIG. 26. The yolk filmtearing step carried out first is the same as that described withrespect to the first aspect of the present invention referring to FIG. 4and FIG. 5. In the following yolk positioning step, the egg 3 positionedin an attitude shown in FIG. 23 is loaded in the heating chambersurrounded by the induction coil 2 a; at that time, the yolk in theeggshell 3 d floats and makes contact with the inner face of theeggshell 3 d as shown in FIG. 24, and the following yolk pattern layerforming step is carried out at this stage; these yolk positioning stepand yolk pattern layer forming step are the same as those described withrespect to the third aspect of the present invention referring to FIG.18 and FIG. 19. In the following yolk/egg white positioning step, theegg 3 having the attitude shown in FIG. 24 is positioned in thevertically reversed attitude shown in FIG. 25; hence, the uncoagulatedyolk 3 g floats in the egg white 3 c, and in contrast therewith, theuncoagulated egg white 3 c sinking downward makes contact with the yolkpattern layer 19 a that is formed by the preceding yolk pattern layerforming step, positioned downward in this stage and attached to theinner face of the eggshell 3 d. The following half egg white skin layerforming step and the half yolk skin layer forming step being carried outsimultaneously therewith are the same as those described with respect tothe first aspect of the present invention referring to FIG. 6 and FIG.7; hence, a half egg white skin layer 9 b is formed along nearly onehalf of the curved surface of the boiled egg, and a half yolk skin layer9 a is formed along nearly the other half of the curved surface.

FIG. 26 is a side view showing the structure of a patterned boiled eggproduced by the serial production steps described above, in a state withthe eggshell 3 d removed. In the figure, the half skin layer 9 b isformed by the egg white 3 c coagulating along nearly one half of thecurved surface of the boiled egg and has a sufficient depth toward thecentral portion; the yolk pattern layer 19 a is formed by the yolk 3 gcoagulating so as to draw a pattern against the background of the halfegg white skin layer 9 b by eliminating the egg white near the curvedsurface of the half egg white skin layer 9 b and has a slight depthtoward the central portion; the half yolk skin layer 9 a is formed bythe yolk 3 g coagulating along nearly the other halt of the curvedsurface of the boiled egg and has a sufficient depth toward the centralportion.

Next, the best mode for embodying the invention set forth in claims 14through 16 will be described below as the fourth aspect of the presentinvention referring to FIG. 27 through FIG. 30. The yolk film tearingstep carried out first is the same as those carried out in the first tofourth aspects; the following yolk positioning step is the same as thatdescribed with respect to the fourth aspect of the present inventionreferring to FIG. 24. However, the yolk pattern layer forming step ischaracterized in that this step is carried out together with the eggwhite pattern layer forming step simultaneously or sequentially. Inorder to form both the pattern layers, as shown in FIG. 27, in theattitude positioned by the yolk positioning step, the egg 3, providedwith the induction heating pattern sheet 2 for forming a yolk patternlayer positioned above and attached to the surface of the eggshell 3 dand an induction heating pattern sheet 27 a for forming an egg whitepattern layer positioned below and attached to the surface of theeggshell 3 d, is loaded in the heating chamber inside the induction coil2 a. By area-selective induction heating for the egg 3, as shown in FIG.28, the yolk pattern layer 19 a is formed and attached to the inner faceof the upper portion of the eggshell 3 d, and at the same time, the eggwhite pattern layer 3 e is formed and attached to the inner face of thelower portion of the eggshell 3 d. In this explanation, the twoinduction heating pattern sheets 2 and 27 a are attached simultaneously,whereby the yolk pattern layer 19 a and the egg white pattern layer 3 eare formed simultaneously; however, the steps for forming both thepattern layers may be independent from each other so as not to belimited in step conditions by attaching the two induction heatingpattern sheets 2 and 27 a at times different from each other and bycarrying out the induction heating treatment at times different fromeach other.

The following yolk/egg white positioning step is a step of verticallyreversing the attitude of the egg 3 as shown in FIG. 29 and is the sameas that described with respect to the fourth aspect of the presentinvention referring to FIG. 25. The following half egg white skin layerforming step and the half yolk skin layer forming step to be carried outsimultaneously therewith are the same as those described with respect tothe first aspect of the present invention referring to FIG. 6 and FIG.7.

FIG. 30 is a side view showing the structure of a patterned boiled eggproduced by the serial production steps described above, in a state withthe eggshell 3 d removed. In the figure, the half egg white skin layer 9b is formed by the egg white 3 c coagulating along nearly one half ofthe curved surface of the boiled egg and has a sufficient depth towardthe central portion; the yolk pattern layer 19 a is formed by the yolk 3g coagulating so as to draw a pattern against the background of the halfegg white skin layer 9 b by eliminating the egg white near the curvedsurface of the half egg white skin layer 9 b and has a slight depthtoward the central portion; the half yolk skin layer 9 a is formed bythe yolk 3 g coagulating along nearly the other half of the curvedsurface of the boiled egg and has a sufficient depth toward the centralportion; the egg white pattern layer 3 e is formed by the egg white 3 ecoagulating so as to draw a pattern against the background of the halfyolk skin layer 9 a and has a slight depth toward the central portion.

Each step itself of the serial production steps in the above-mentionedexplanations can be replaced with another known step. For example, theegg white pattern layer forming step itself or the yolk pattern layerforming step itself may be a step wherein a pattern is drawn on theuncoagulated egg white or the uncoagulated yolk inside the eggshell byheating the surface of the eggshell area-selectively and concentricallythrough the manual operation of an electric iron 31 a shown in FIG. 31.Furthermore, for example, as shown in FIG. 32, the yolk film tearingstep may be a step of tearing the film by manually operating a thinneedle 32 a made of steel so that the tip 32 b of the thin needle havingpassed through part of the eggshell 3 d further passes through the yolkfilm 3 f.

INDUSTRIAL APPLICABILITY

As described above, the present invention provides an ornamentalexpression by forming patterns in two colors, white and yellow, on thecurved surface of a boiled egg in a state with its eggshell removed, byusing the yolk and egg white, the original contents inside the eggshell,as materials and by only selectively applying heat and acceleration,without providing any mechanical process for the eggshell and withoutintroducing any materials into the eggshell from outside the eggshell.Hence, two trade-off requests, i.e., the removal of anxiety in foodhygiene control and the improvement in tastefulness on the dining table,are fulfilled, whereby consumers can have satisfaction with respect totastefulness on the dining table, whereby the industrial applicabilityof the present invention is very high.

I claim:
 1. A patterned boiled egg comprising: a half yolk skin layerformed of a yolk coagulating along nearly one half of the curved surfaceof said boiled egg; an egg white pattern layer formed of an egg whitecoagulating so as to draw a pattern against the background of said halfyolk skin layer while eliminating the yolk near the curved surfaceinside said half yolk skin layer of said boiled egg; and a half eggwhite skin layer formed of the egg white coagulating along nearly theother half of the curved surface of said boiled egg.
 2. A method forproducing a patterned boiled egg including a series of production stepscomprising: an egg white pattern layer forming step for forming an eggwhite pattern layer so as to draw a pattern by heating a specificpattern area drawn on nearly one half of the curved surface of theeggshell of an egg area-selectively and concentrically, by coagulatingan uncoagulated egg white on the inner face of said eggshell, and byremovably attaching said egg white to the inner face of said eggshell; ayolk film tearing step for tearing the yolk film of said egg after saidegg white pattern layer forming step; a yolk positioning step forpositioning an uncoagulated yolk after said yolk film tearing step byfloating said uncoagulated yolk in the egg white inside said eggshelland by positioning said yolk so that said uncoagulated yolk surroundssaid egg white pattern layer attached to the inner face of said eggshelland makes contact with said egg white pattern layer; a half yolk skinlayer forming step for forming a half yolk skin layer along nearly onehalf of said curved surface of said egg by boiling said egg after saidyolk positioning step in its stationary posture as it is in a heatingmedium, such as hot water, and by coagulating said uncoagulated yolkfloating in said egg white inside said eggshell so that saiduncoagulated yolk surrounds said egg white pattern layer, makes contactwith said egg white pattern layer and becomes the background of said eggwhite pattern layer; and a half egg white skin layer forming step,proceeding simultaneously with said half yolk skin layer step, forforming a half egg white skin layer along nearly the other half of saidcurved surface of said egg by boiling said egg after said yolkpositioning step in its stationary posture as it is in a heating medium,such as hot water, and by coagulating said egg white sinking below saiduncoagulated yolk floating inside said eggshell.
 3. A method forproducing a patterned boiled egg set forth in claim 2, wherein said yolkfilm tearing step is a rotating/stopping yolk film tearing step fortearing said yolk film, during the rotation of said egg around the majoraxis of said egg at a high speed, by immediately stopping said rotationand by applying a shearing force owing to the difference between theinertial force acting on the yolk at the central portion inside saideggshell and the inertial force acting on the egg white at theperipheral portion to said yolk film at the time of said immediate stop.4. A patterned boiled egg comprising: a whole yolk skin layer formed ofa yolk coagulating along the whole curved surface of said boiled egg;and an egg white pattern layer formed of an egg white coagulating so asto draw a pattern against the background of said whole yolk skin layerwhile eliminating the yolk near said curved surface inside said wholeyolk skin layer of said boiled egg.
 5. A method for producing apatterned boiled egg including a series of production steps comprising:an egg white pattern layer forming step for forming an egg white patternlayer so as to draw a pattern by heating a specific pattern area drawnon nearly one half of the curved surface of the eggshell of an eggarea-selectively and concentrically, by coagulating an uncoagulated eggwhite on the inner face of said eggshell, and by removably attachingsaid egg white to the inner face of said eggshell; a yolk film tearingstep for tearing the yolk film of said egg after said egg white patternlayer forming step; and a whole yolk skin layer forming step for forminga whole yolk skin layer along the whole curved surface of said egg so asto become the background of said egg white pattern layer by sequentiallyexposing the whole face of the curved surface of said egg to a heatingenvironment while rotating said egg after said yolk film tearing step,by floating the yolk in the egg white inside said eggshell, by attachingsaid yolk to said eggshell and by sequentially coagulating theuncoagulated yolk surrounding said egg white pattern layer and makingcontact with said egg white pattern layer near the inner face of saideggshell at the portion exposed to said heating environment duringrotation and rocking or immediately after rotation and rocking.
 6. Amethod for producing a patterned boiled egg set forth in claim 5,wherein said whole yolk skin layer forming step comprises: a centralportion yolk skin layer forming step for forming a central portion yolkskin layer along the curved surface of a portion corresponding to thecentral portion along the major axis of said curved surface of an egg bysequentially exposing the portion corresponding to the central portionalong the major axis of said curved surface of said egg to an upperheating environment while rotating said egg around the major axis ofsaid egg as a horizontal rotation center axis, and by sequentiallycoagulating the uncoagulated yolk floating in the egg white inside saideggshell and attached to said eggshell near the inner face of the upperportion of said eggshell exposed to the heating environment during saidrotation; an acute end portion yolk skin layer forming step for formingan acute end portion yolk skin layer along the curved surface of theacute end portion by exposing said acute end portion of said egg to anupper heating environment while rotating said egg around the major axisof said egg as an inclined vertical rotation center axis, and bycoagulating the uncoagulated yolk floating in the egg white inside saideggshell at said acute end portion and attached to said eggshell; and anobtuse end portion yolk skin layer forming step for forming an obtuseend portion yolk skin layer along the curved surface of the obtuse endportion after said acute end portion yolk skin layer forming by boilingsaid egg in a heating medium, such as hot water, in a stationary posturewherein the major axis of said egg extends vertically and said obtuseend portion is positioned upward, and by coagulating the uncoagulatedyolk floating in the egg white inside said eggshell at said obtuse endportion and attached to said eggshell.
 7. A method for producing apatterned boiled egg set forth in claim 5, wherein said whole yolk skinlayer forming step is a rotating/rocking whole yolk skin layer formingstep for forming a whole yolk skin layer along the whole curved surfaceof an egg by boiling said egg while rotating and rocking said egg aroundthe major axis of said egg used as its rotation and rocking center axisin a state wherein said egg is wholly dipped in a heating medium, suchas hot water, and by coagulating the uncoagulated yolk, which isrelatively easy to coagulate, floating near the inner face of the upperportion of said eggshell and attached to the eggshell, earlier than theuncoagulated egg white, which is relatively difficult to coagulate,sinking near the inner face of the lower portion of said eggshell andattached to said eggshell, during said rotation and rocking.
 8. Apatterned boiled egg comprising: a whole egg white skin layer formed ofan egg white coagulating along the whole curved surface of said boiledegg; and a yolk pattern layer formed of a yolk coagulating so as to drawa pattern against the background of said whole egg white skin layerwhile eliminating the yolk near said curved surface inside said wholeegg white skin layer of said boiled egg.
 9. A method for producing apatterned boiled egg including a series of production steps comprising:a yolk film tearing step for tearing the yolk film of an egg; a yolkpositioning step for positioning an uncoagulated yolk after said yolkfilm tearing step by floating said uncoagulated yolk in the egg whiteinside the eggshell and by positioning said uncoagulated yolk so thatsaid uncoagulated yolk makes contact with the inner face of saideggshell; a yolk pattern layer forming step for forming a yolk patternlayer so as to draw a pattern after said yolk positioning step byheating a specific pattern area drawn on nearly one half of the curvedsurface of said eggshell area-selectively and concentrically, bycoagulating said uncoagulated yolk on the inner face of said eggshell,and by removably attaching said yolk to the inner face of said eggshell;a whole egg white skin layer forming step for forming a whole egg whiteskin layer along the whole curved surface of said egg after said yolkpattern forming step by boiling said egg while rotating and rocking saidegg around the major axis of said egg used as its rotating/rockingcenter axis in a state wherein said egg is partially dipped in a heatingmedium, such as hot water, and by coagulating the uncoagulated eggwhite, which is relatively difficult to coagulate, sinking near theinner face of the lower portion of said eggshell dipped in said heatingmedium and attached to said eggshell, earlier than the uncoagulatedyolk, which is relatively easy to coagulate, floating near the innerface of the upper portion of said eggshell not dipped in said heatingmedium and attached to said eggshell, during said rotation and rocking,so that said uncoagulated egg white surrounds said yolk pattern layerattached to the inner face of said eggshell, makes contact with saidyolk pattern layer and becomes the background of said yolk patternlayer.
 10. A method for producing a patterned boiled egg set forth inclaim 9, wherein said yolk film tearing step is a rotating/stopping yolkfilm tearing step for tearing said yolk film, during the rotation ofsaid egg around the major axis of said egg at a high speed, byimmediately stopping said rotation and by applying a shearing forceowing to the difference between the inertial force acting on the yolk atthe central portion inside said eggshell and the inertial force actingon the egg white at the peripheral portion to said yolk film at the timeof said immediate stop.
 11. A patterned boiled egg comprising: a halfegg white skin layer formed of an egg white coagulating along nearly onehalf of the curved surface of said boiled egg; a yolk pattern layerformed of a yolk coagulating so as to draw a pattern against thebackground of said half egg white skin layer while eliminating the eggwhite near said curved surface inside said half egg white skin layer ofsaid boiled egg; and a half yolk skin layer formed of a yolk coagulatingalong nearly the other half of said curved surface of said boiled egg.12. A method for producing a patterned boiled egg including a series ofproduction steps comprising: a yolk film tearing step for tearing theyolk film of an egg; a yolk positioning step for positioning anuncoagulated yolk after said yolk film tearing step floating saiduncoagulated yolk in the egg white inside the eggshell and bypositioning said uncoagulated yolk so that said uncoagulated yolk makescontact with the inner face of said eggshell; a yolk pattern layerforming step for forming a yolk pattern layer so as to draw a pattern byheating a specific pattern area drawn on nearly one half of the curvedsurface of said eggshell after said yolk positioning steparea-selectively and concentrically, by coagulating said uncoagulatedyolk on the inner face of said eggshell, and by removably attaching saidyolk to the inner face of said eggshell; a yolk/egg white positioningstep for positioning said uncoagulated yolk by floating saiduncongulated yolk in said egg white inside said eggshell so that saidyolk makes contact with nearly the other half of the inner face of saideggshell of said egg after said yolk pattern layer forming step, and forpositioning an uncoagulated egg white by sinking said egg white so thatsaid uncoagulated egg white surrounds said yolk pattern layer attachedto nearly one half of the inner face of said eggshell of said egg andmakes contact with said yolk pattern layer; a half egg white skin layerforming step for forming a half egg white skin layer along nearly onehalf of the curved surface of said egg by boiling said egg after saidyolk/egg white positioning step in its stationary posture as it is in aheating medium, such as hot water, and by coagulating said uncoagulatedegg white so that said uncoagulated egg white sinks below saiduncoagulated yolk floating inside said eggshell, surrounds said yolkpattern layer, makes contact with said yolk pattern layer and becomesthe background of said yolk pattern layer; and a half yolk skin layerforming step, proceeding simultaneously with said half egg white skinlayer forming step, for forming a half yolk skin layer along nearly theother half of the curved surface of said egg by boiling said egg aftersaid yolk/egg white positioning step in its stationary posture as it isin a heating medium, such as hot water, and by coagulating saiduncoagulated yolk floating in said egg white inside said eggshell.
 13. Amethod for producing a patterned boiled egg set forth in claim 12,wherein said yolk film tearing step is a rotating/stopping yolk filmtearing step for tearing said yolk film, during the rotation of said eggaround the major axis of said egg at a high speed, by immediatelystopping said rotation and by applying a shearing force owing to thedifference between the inertial force acting on the yolk at the centralportion inside said eggshell and the inertial force acting on the eggwhite at the peripheral portion to said yolk film at the time of saidimmediate stop.
 14. A patterned boiled egg comprising: a half egg whiteskin layer formed of an egg white coagulating along nearly one half ofthe curved surface of said boiled egg; a yolk pattern layer formed of ayolk coagulating so as to draw a pattern against the background of saidhalf egg white skin layer while eliminating the egg white near saidcurved surface inside said half egg white skin layer of said boiled egg;a half yolk skin layer formed of a yolk coagulating along nearly theother half of the curved surface of said boiled egg; and an egg whitepattern layer formed of an egg white coagulating so as to draw a patternagainst the background of said half yolk skin layer while eliminatingthe yolk near said curved surface inside said half yolk skin layer ofsaid boiled egg.
 15. A method for producing a patterned boiled eggincluding a series of production steps comprising: a yolk film tearingstep for tearing the yolk film of an egg; a yolk positioning step forpositioning an uncoagulated yolk after said yolk film tearing step byfloating said uncoagulated yolk in the egg white inside the eggshell andby positioning said uncoagulated yolk so that said uncoagulated yolkmakes contact with the inner face of said eggshell; a yolk pattern layerforming step for forming a yolk pattern layer so as to draw a pattern byheating a specific pattern area drawn on nearly one half of the curvedsurface of said eggshell after said yolk positioning steparea-selectively and concentrically, by coagulating said uncoagulatedyolk on the inner face of said eggshell, and by removably attaching saidyolk to the inner face of said eggshell; an egg white pattern layerforming step for forming an egg white pattern layer so as to draw apattern by heating a specific pattern area drawn on nearly the otherhalf of the curved surface of said eggshell after said yolk positioningstep area-selectively and concentrically, by coagulating an uncoagulatedegg white on the inner face of said eggshell, and by removably attachingsaid egg white to the inner face of said eggshell; a yolk/egg whitepositioning step for positioning said uncoagulated yolk by floating saiduncoagulated yolk in said egg white inside said eggshell so that saiduncoagulated yolk surrounds said egg white pattern layer attached tonearly the other half of the inner face of said eggshell of said egg andmakes contact with said egg white pattern layer after both said yolkpattern layer forming step and said egg white pattern layer formingstep, and for positioning said uncoagulated egg white by sinking saiduncoagulated egg white so that said uncoagulated egg white surroundssaid yolk pattern layer attached to nearly one half of the inner face ofsaid eggshell of said egg and makes contact with said yolk patternlayer; a half egg white skin layer forming step for forming a half eggwhite skin layer along nearly one half of the curved surface of said eggby boiling said egg after said yolk/egg white positioning step in itsstationary posture as it is in a heating medium, such as hot water, andby coagulating said uncoagulated egg white so that said uncoagulated eggwhite sinks below said uncoagulated yolk floating inside said eggshell,surrounds said yolk pattern layer, makes contact with said yolk patternlayer and becomes the background of said yolk pattern layer; and a halfyolk skin layer forming step, proceeding simultaneously with said halfegg white skin layer forming step, for forming a half yolk skin layeralong nearly the other half of the curved surface of said egg by boilingsaid egg after said yolk/egg white positioning step in its stationaryposture as it is in a heating medium, such as hot water, and bycoagulating said uncoagulated yolk so that said uncoagulated yolk floatsin said egg white inside said eggshell, surrounds said egg white patternlayer, makes contact with said egg white pattern layer and becomes thebackground of said yolk pattern layer.
 16. A method for producing apatterned boiled egg set forth in claim 15, wherein said yolk filmtearing step is a rotating/stopping yolk film tearing step for tearingsaid yolk film, during the rotation of said egg around the major axis ofsaid egg at a high speed, by immediately stopping said rotation and byapplying a shearing force owing to the difference between the inertialforce acting on the yolk at the central portion inside said eggshell andthe inertial force acting on the egg white at the peripheral portion tosaid yolk film at the time of said immediate stop.